U.S. Pat. Nos. 6,382,962, 6,585,510, 6,589,047, and 6,663,384 disclose various venting devices (plates and chassis) that are used atop containerized (jar) candles to improve combustion and reduce soot. The venting plates of U.S. Pat. No. 6,382,962 are flat discs that have several inlet vents radially spaced from a central exhaust vent so as to provide separated laminar inlet and exhaust air flows. The venting chassis of U.S. Pat. Nos. 6,585,510, 6,589,047, and 6,663,384 provide a substructure upon which various ornamentation and decorative reliefs are mounted, as well as facilitating laminar air flow within the jar candle. The ornamentation and decorative reliefs are bonded to the top of the venting chassis around a central chimney through which exhaust air is vented. The venting chassis is supported atop the candle by a number of feet which space the chassis over the brim of the candle to create an annular inlet vent. The venting chassis also include an internal baffle for physically separating the inlet and exhaust air flows within the vessel interior. The baffle directs inlet air flow downward into the interior of the candle through the inlet vent downward along the sidewalls of the vessel and separates the downward inlet air flow from the upward exhaust air flow. In addition to creating separated laminar inlet and exhaust airflows within jar candles, which improves combustion and reduces soot, these venting devices help regulate the surface temperature of the jar candle by venting cool inlet air downward along the jar sidewalls. This cooling function helps to insure that the jar candle can be safely handled and operated by a user.
The above mentioned venting devices are designed to work optimally with standard “three inch” apothecary jar candles. The descriptive term “three inch” refers to the diameter of the jar's mouth. In the candle industry, apothecary jars typically conform to certain basic dimensional standards whether constructed from blown or I.S. glass insure use with automated filling systems. The body diameter of a standard “three inch” apothecary jar is approximately 4.0 inches and the mouth diameter is approximately 3.26 inches (83 mm) for blown glass and 3.50 inches (89 mm) for I.S. glass. While varying in height three to six inches, the dimension of a typical apothecary jar varies very little, only a few tenths of an inch, particularly in the diameters of the body and mouth. Heretofore, while working optimally with standard three inch apothecary jar candles, these venting plates and venting chassis have not worked optimally with jar candles that have small diameter mouths, or jar candles that have oddly shaped, non-cylindrical or smaller sized jars.
The venting and cooling functions of the above mentioned venting devices are critically effected by the area, diameter and configuration of both the jar mouth and the jar interior. Small mouthed jar candles (typically diameters less than 3.26 inches) are particularly problematic simply because there is less area in which to separate the inlet airflow from the exhaust airflow. Because both inlet and exhaust air must both physically pass through the jar's mouth, smaller mouthed jar candles physically limit the venting device's capability to sufficiently separate the inlet and exhaust air flows. Non-cylindrical and oddly shaped jar candles also present significant venting problems, particularly jars with pronounced shoulders between the sidewalls and brim of the jars. In most candle jars, the brim of the jar mouth is inset some distance from the sidewall of the jar forming a pronounced shoulder interior. Because the skirts or baffles of conventional venting plates and chassis direct the inlet air flows directly downward, an air gap is formed beneath these pronounced shoulders in the jars and the cool inlet air flow is not vented directly out to the sidewalls from the inset jar mouth. Furthermore, conventional venting plates and chassis cannot direct inlet air flow back onto angled and curved sidewalls of the many oddly shaped jar candles that are available.
The cooling function provided by a venting device becomes more critical as the volume or the jar and the area of the jar mouth decreases. The smaller volume jar candles have less interior within which the thermal energy of the candle can be diffused. Consequently, the surface temperature of the jar, the melted wax pool and internal air temperature is higher in smaller jar candles than in standard three inch apothecary jar candles. In smaller sized jar candles, the surface temperature can often be too hot to touch and more even elevate to the flash point of the wax, presenting serious fire and safety hazards.